This summer, social media platforms like TikTok and Instagram have seen a rise in users tracking the daily UV index, not to avoid sun exposure but to seek it out during peak hours for tanning. This trend has prompted concern among dermatologists as some influencers also claim that sunscreen is either unnecessary or harmful.
Y. Linda Liou, DO, assistant clinical professor in the Department of Dermatology at UC San Diego School of Medicine, addressed these issues by explaining how the UV index works and highlighting the risks associated with intentional sun exposure. “I actually love that people are paying attention to the UV index — it means they’re thinking about sun exposure. But what worries me is how it’s being used: instead of avoiding high UV times, people are chasing them to tan faster. A tan may look like a glow, but it’s really your skin’s SOS signal that DNA damage has already happened. You don’t see it right away, but the harm is happening underneath,” Liou said.
Liou described the UV index as “basically a weather report for how strong the sun’s radiation is,” noting factors such as time of day and cloud cover affect its value. The scale ranges from 1 to 11+, with higher numbers indicating a greater risk of skin damage in less time. She added that even those with darker skin tones are susceptible to cumulative UV damage.
Discussing short- and long-term effects of deliberate tanning during peak UV hours, Liou stated: “When you lay out during peak UV, you’re getting a blast of radiation at its strongest. On the surface you might see a tan or burn, but underneath, UV rays are breaking DNA, stressing out skin cells and weakening your skin’s immune defenses.” She explained that while darker skin tones do not burn as easily as lighter ones, they are still vulnerable to conditions like hyperpigmentation and late-diagnosed skin cancers.
Liou also dispelled myths about tanning safety: “One of the biggest myths is that a ‘base tan’ protects you. The truth is, a tan is your skin’s response to damage — it translates to your cells pumping out melanin… Even the darkest natural skin tones don’t block UV completely, so no one is off the hook.”
On concerns regarding sunscreen safety raised online, Liou responded: “It’s easy to feel overwhelmed by all the mixed messages online. But here’s the fact: sunscreen is safe, effective, and one of the simplest ways to prevent skin cancer and premature aging.” She addressed specific misconceptions around toxicity—pointing out animal studies do not reflect typical human use—and environmental impact by recommending mineral or “reef-safe” sunscreens when appropriate.
Liou recommended practical steps for enjoying sunny days safely: staying in shade when possible; timing outdoor activities before 9 a.m. or after 4 p.m.; using broad-spectrum SPF 30+; reapplying every 90 minutes; wearing UPF-rated clothing and wide-brim hats; and using sunglasses for eye protection. She mentioned laundry additives like SunGuard can add UV protection to existing clothes and noted that certain dietary supplements may provide limited backup protection.
Her advice concluded with an emphasis on prevention: “I hear this often from my older patients with skin cancers: ‘I wish I had worn more sunscreen when I was younger.’ Right now, you have tons of options — lotions, sprays… There’s truly something for everyone… Protect it now, and your older self will thank you.”
